Luminorefrigeration: vibrational cooling of NaCs.

We demonstrate the use of optical pumping of kinetically ultracold NaCs to cool an initial vibrational distribution of electronic ground state molecules X(1)Σ(+)(v ≥ 4) into the vibrational ground state X(1)Σ(+)(v=0). Our approach is based on the use of simple, commercially available multimode diode lasers selected to optically pump population into X(1)Σ(+)(v=0). We investigate the impact of the cooling process on the rotational state distribution of the vibrational ground state, and observe that an initial distribution, J(initial)=0-2 is only moderately affected resulting in J(final)=0-4. This method provides an inexpensive approach to creation of vibrational ground state ultracold polar molecules.

Photoassociation studies of ultracold NaCs from the Cs 6(2)P(3/2) asymptote.

A combination of pulsed depletion spectroscopy and photoassociation spectroscopy is utilized to assign photoassociation spectra of NaCs. These methods investigate the ab initio Ω = 2 potential energy curve and indicate a previously unknown avoided crossing between the (3)Ω = 1 and (4)Ω = 1 electronic states. We present rotational assignments of deeply bound singlet ground state molecules, an improved C(6) coefficient for the (4)Ω = 1 and assignments for all twenty-three photoassociation resonances detuned from the Cs 6(2)P(3/2) asymptote.

Creation and detection of Skyrmions in a Bose-Einstein condensate.

We present the first experimental realization and characterization of two-dimensional Skyrmions and half-Skyrmions in a spin-2 Bose-Einstein condensate. The continuous rotation of the local spin of the Skyrmion through an angle of pi (and half-Skyrmion through an angle of pi/2) across the cloud is confirmed by the spatial distribution of the three spin states as parametrized by the bending angle of the l vector. The winding number w = (0,1,2) of the internal spin states comprising the Skyrmions is confirmed through matter-wave interference.

Manufacturing a thin wire electrostatic trap for ultracold polar molecules.

We present a detailed description on how to build a thin wire electrostatic trap (TWIST) for ultracold polar molecules. It is the first design of an electrostatic trap that can be superimposed directly onto a magneto-optical trap (MOT). We can thus continuously produce ultracold polar molecules via photoassociation from a two species MOT and instantaneously trap them in the TWIST without the need for complex transfer schemes. Despite the spatial overlap of the TWIST and the MOT, the two traps can be operated and optimized completely independently due to the complementary nature of the utilized trapping mechanisms.

Studies of two-species Bose-Einstein condesation.

We describe our recent progress on the investigation of two-species Bose-Einstein condensation. From a theoretical analysis we show that there is a new rich phenomenology associated with two-species Bose-Einstein condensates which does not exist in a single-species condensate. We then describe results of a numerical model of the evaporative cooling process of a trapped two-species gas.

On-chip optical detection of laser cooled atoms.

We have used an optical fiber based system to implement optical detection of atoms trapped on a reflective "atom-chip". A fiber pair forms an emitter-detector setup that is bonded to the atom-chip surface to optically detect and probe laser cooled atoms trapped in a surface magneto-optical trap. We demonstrate the utility of this scheme by measuring the linewidth of the Cs D2 line at different laser intensities.

An all optical dynamical dark trap for neutral atoms.

We describe the experimental realization of a dynamical optical trap for atoms: the Rotating Off-resonant Dipole Optical (RODiO) Trap. A blue detuned circularly scanned laser beam creates a time averaged ;;box" for the atoms. We characterized this novel confinement technique by varying the trapping geometry and the laser beam parameters. Our observations agree well with a numerical model.

Flow cytometric reticulocyte analysis. Multiinstitutional interlaboratory correlation study.

Reticulocyte analysis by flow cytometry offers precision and sensitivity greater than those of conventional morphologic methods and permits derivation of a reticulocyte maturity index. However, interlaboratory variability has not yet been reported. The authors analyzed 310 samples at eight sites using 11 instruments over a 4-month period to examine intermethod and interlaboratory variabilities. Stains included thiazole orange, ethidium bromide, and auramine O. Instruments included models by Coulter, Becton Dickinson, TOA Medical Electronics, and Ortho Diagnostics. The coefficient of variation (CV) among all sites and methods on these samples varied as a function of the reticulocyte percentage, ranging from a mean CV of 69% for samples with < .5% reticulocytes to 24.1% for those with > 2.5% reticulocytes. The best performance was observed with the TOA R-1000 dedicated reticulocyte analyzers, with a mean CV of 18.4% for samples with < .5% reticulocytes and 4.6% for samples with > 2.5% reticulocytes. The reticulocyte maturity index showed comparable intersite precision, with a mean CV of 16% for samples with > 2.5% reticulocytes with multipurpose flow cytometers and a mean CV of 7.3% with the TOA R-1000 instruments. Interclass correlations among all sites ranged from .79 to .99 for the reticulocyte counts and .41 to .88 for the reticulocyte maturity index. The authors conclude that flow cytometric reticulocyte analysis is more precise than manual reticulocyte analysis. With greater automation of this methodology, further interlaboratory standardization of reticulocyte counts and the reticulocyte maturity index can be achieved.

Flow cytometric reticulocyte analysis and the reticulocyte maturity index.

Reticulocyte analysis has evolved to one of the accepted and routinely practiced clinical applications of flow cytometry technology. Similar to CD4 measurements, FCM technology has contributed to documented improvements in reticulocyte counting precision over previous microscope-based techniques. The ability to FCM instruments to quantitate fluorescence intensity has been utilized to derive a parameter of reticulocyte maturity, which we have termed the reticulocyte maturity index. The FCM-derived RMI parameter offers an additional perspective to assess the erythropoietic response in anemic patients over reticulocyte counting alone and provides further insight into the differential diagnosis of anemia. Clinical utility of the RMI has been reported in monitoring expensive, new-technology therapies, such as bone marrow transplantation and erythropoietin therapy. FCM reticulocyte analysis is still not fully mature, but is in a state of continued evolution. Needs exist for (i) improved software for data analysis, (ii) newer automation techniques to improve interlaboratory correlations, and (iii) further validation and refinement of the reticulocyte maturity index parameter.

Adaptation to eccentric exercise: effect on CD64 and CD11b/CD18 expression.

The primary purpose of the study was to examine circulating neutrophils and monocytes and their plasma membrane expression of CD64, CD11b, and CD18 after two bouts (B1 and B2) of eccentric exercise. Subjects (n = 10) performed 25 forced-lengthened contractions of the forearm flexors on two occasions separated by 3 wk. Blood samples were obtained before exercise and at 1.5, 6, 12, 24, 48, 72, and 96 h of recovery. CD64, CD11b, and CD18 expression was determined via direct immunofluorescence and used as an indicator of neutrophil and monocyte activation. Creatine kinase activity (B1 = 1,390, B2 = 108 U/l), myoglobin (B1 = 163, B2 = 41, ng/dl), and muscle soreness and tenderness were higher (P < 0.01) after B1 compared with B2. Neutrophils at 6, 12, and 96 h were higher (P < 0.05) for B1 vs. B2. CD11b expression on neutrophils was 2.7-fold higher at 72 h for B1 vs. B2. CD64 expression on neutrophils at 72 and 96 h was 1.4- and 1.9-fold higher, respectively, for B1 vs. B2. At 72 and 96 h, CD18 and CD64 expression on monocytes was 1.3-fold higher for B1 vs. B2. The observed changes were not significantly correlated with changes in creatine kinase activity or myoglobin. In conclusion, the adaptation to eccentric arm exercise was associated with a reduction in circulating neutrophils and a lower state of neutrophil and monocyte activation.

Strategies for molecular characterisation of methicillin- and gentamicin-resistant Staphylococcus aureus in a Canadian nosocomial outbreak.

Sixteen methicillin-resistant Staphylococcus aureus (MRSA) isolates, from a single nosocomial outbreak, were tested for molecular and phenotypic relationships. Two of the 16 outbreak strains were gentamicin resistant (Gmr) and the plasmids that they carried were characterised by reverse field electrophoresis, restriction endonuclease analysis and gene hybridisation. The gentamicin-resistant (Gmr) strains harboured two plasmids, a Gmr plasmid of 36.5 kb and a cryptic plasmid of 25.4 kb, whereas the other 14 isolates contained only the cryptic plasmid. Gentamicin resistance was encoded by a 2.5-kb HindIII fragment of the 32.8-kb plasmid and is similar to the 2.5-kb HindIII fragment also described for S. aureus Gmr plasmids from Australia and the USA. The Gmr plasmid was non-conjugal and was cured by ethidium bromide at a frequency of 4%. Two MRSA strains isolated subsequently from the same hospital were also Gmr and had identical plasmid and restriction endonuclease profiles to the two Gmr strains studied initially. Two other S. aureus isolates from the original carrier detected in this study and from his son were methicillin and gentamicin susceptible and had novel profiles. Since large plasmids show anomalous migration in agarose gels, more definitive analyses than simple plasmid identification should be considered when studying nosocomial outbreaks.

Automated reticulocyte analysis. Clinical practice and associated new parameters.

Automated reticulocyte analysis, through continued instrument, software, and reagent developments, provides improved precision for the reticulocyte count. This rapid and simple testing assists in providing a cost effective and sensitive approach to the diagnosis and therapeutic monitoring of the anemic patient. As laboratory and clinical hematologist become familiar with the benefits and expanding clinical applications of this technology, the use of reticulocyte analysis will increase.

Exercise-induced muscle damage: effect on circulating leukocyte and lymphocyte subsets.

The purpose of this study was to determine the effect of downhill and level running on circulating leukocyte and lymphocyte subsets and T lymphocyte activation. Using a random cross-over design, 10 runners completed two trials of 60 min of level running (0% grade; LR) and downhill running (-10% grade; DHR) at 70% of level VO2max. Blood samples were obtained preexercise and immediately postexercise (POST) and at 1.5, 12, 24, and 48 h of recovery. Creatine kinase activity peaked at 12 h of recovery from DHR and was not significantly altered following LR. The number of total T, CD16+, CD3+CD56+ cells were significantly higher POST DHR compared with LR. Leukocyte and neutrophil counts were significantly higher at 1.5 and 12 h of recovery from DHR compared with LR. The number of activated CD8+ cells (CD25+ CD8+) was significantly higher at 12 h of DHR compared to LR. Total T cells were significantly reduced at various time points during the 48 h of recovery from LR and DHR. In summary, DHR relative to LR resulted in a greater mobilization of lymphocytes (post), neutrophils (1.5-12 h of recovery) and activation of CD8+ cells at 12 h of recovery. In addition, reductions in circulating T lymphocyte subsets occurred following both conditions.

Flow cytometric reticulocyte quantification using thiazole orange provides clinically useful reticulocyte maturity index.

Flow cytometric reticulocyte quantification with thiazole orange has been reported to be of potential utility in a clinical hematology laboratory. We have instituted this technique into routine clinical testing for 18 months and we describe this experience. Flow cytometric analysis provided not only reproducible, cost-effective reticulocyte quantification, but a quantitative reticulocyte maturity index proportional to the amount of RNA in the reticulocytes. The reticulocyte maturity index measurement represents an independent parameter of erythropoiesis, which provided clinically valuable information regarding bone marrow engraftment in patients following autologous bone marrow transplantation. The findings of this study demonstrate the clinical utility of thiazole orange reticulocyte analysis and indicate the diagnostic importance of the reticulocyte maturity index measurement in the evaluation of erythropoietic activity.

Sculpting the vortex state of a spinor BEC.

We use Raman-detuned laser pulses to achieve spatially varying control of the amplitude and phase of the spinor order parameter of a Bose-Einstein condensate. We present experimental results confirming precise radial and azimuthal control of amplitude and phase during the creation of vortex-antivortex superposition states.

Phases of atom-molecule vortex matter.

We study ground state vortex configurations in a rotating atom-molecule Bose-Einstein condensate. It is found that the coherent coupling between the atomic and molecular condensates can render a pairing of atomic and molecular vortices into a composite structure that resembles a carbon dioxide molecule. Structural phase transitions of vortex lattices are also explored through different physical parameters including the rotational frequency of the system.

Trapping of ultracold polar molecules with a thin-wire electrostatic trap.

We describe the realization of a dc electric-field trap for ultracold polar molecules, the thin-wire electrostatic trap (TWIST). The thin wires that form the electrodes of the TWIST allow us to superimpose the trap onto a magneto-optical trap (MOT). In our experiment, ultracold polar NaCs molecules in their electronic ground state are created in the MOT via photoassociation, achieving a continuous accumulation in the TWIST of molecules in low-field seeking states. Initial measurements show that the TWIST trap lifetime is limited only by the background pressure in the chamber.

Structural phase transitions of vortex matter in an optical lattice.

We consider the vortex structure of a rapidly rotating trapped atomic Bose-Einstein condensate in the presence of a corotating periodic optical lattice potential. We observe a rich variety of structural phases which reflect the interplay of the vortex-vortex and vortex-lattice interactions. The lattice structure is very sensitive to the ratio of vortices to pinning sites and we observe structural phase transitions and domain formation as this ratio is varied.